Photographic processes for forming a silver image by diffusion transfer are well known. Processes for forming a usable negative image along with a positive silver transfer image are also known. In a typical process, a light-sensitive silver halide emulsion which has been exposed to actinic radiation is contacted with an aqueous alkaline processing composition including a silver halide solvent and a silver halide developing agent whereby exposed and developable silver halide is reduced to metallic silver to form a negative image, and substantially contemporaneously an imagewise distribution of a soluble silver complex is formed as a function of unexposed areas of the emulsion. This imagewise distribution is transferred by diffusion to a superposed image-receiving layer where it is reduced to metallic silver to form a positive silver transfer image. After this transfer of image-forming silver, the negative image component is separated from the positive silver transfer image -- the processing composition including the silver halide developing agent being adhered to the surface of the negative component. If allowed to remain, adherence of the developing agent to the negative component after separation from the positive element will adversely affect the quality of the negative image since unoxidized developing agent will react with atmospheric oxygen to form a color product which forms stains, and oxidation products of developing agent have a tendency to oxidize silver, thereby causing the negative image to fade or lose density.
To obviate the above-mentioned problems, it has heretofore been customary to subject at least the negative image to an immediate after-treatment, e.g., a washing, in order to remove residual developing agent.
It has been discovered that this immediate washing may be delayed for extended periods of time if the surface of the developer layer can be protected from uneven oxygen exposure while the moisture is allowed to leave through a uniformly thick layer of a class of protective materials.